Conventional corneal transplantation surgery, also known as penetrating keratoplasty, uses full-thickness corneal replacement with sutures. Recently, deep lamellar endothelial keratoplasty (DLEK) has been used to place a partial-thickness corneal replacement from a healthy donor cornea into a host/recipient along with its endothelium. DLEK is also known as “stitchless” corneal transplantation.
Some researchers and physicians believe that DLEK is a major advance in the way that diseased human cornea is replaced with healthy donor corneal endothelium. An exemplary transplantation procedure of a conventional donor harvesting and recipient preparation is described in Thomas John, Stitchless Corneal Transplantation, Cataract & Refractive Surgery Today, pp. 27-30, August 2004. As described, a donor corneal endothelium is coated with viscoelastic material and the cornea and its attached scleral rim are placed in an artificial chamber. After excision of the anterior stromal disc, the donor corneal stroma can be flipped on itself so that the donor corneal stroma rests on a Teflon® block with the stromat side facing down and is held in place via vacuum. Trephination can be carried using a MORIA trephine. The deep stromal-endothelia donor disc can be carefully placed onto a viscoelastic-coated Ousley spatula (available from Bausch & Lomb) with the endothelial side facing down.
More recently, a smaller incision DLEK technique has been proposed in which the donor disc (usually between about 8-8.25 mm in diameter) can be held by simple forceps. In this procedure, the surgeon folds the transplant in half (endothelial side down) and inserts the transplant material through a 5 mm incision into the host anterior chamber (under air) and onto the host bed of the pre-resected central area. Instrastromal Cindy scissors can be used in a free hand manner to excise the recipient disc using about an 8 mm circular ink mark on an epithelial surface as a visual template. A separate tool is typically used to manipulate the tissue into position. Once in the anterior chamber, the folded donor disc is irrigated with saline to remove viscoelastic material, opened further with an air bubble (which can be decreased in size), then rolled over the air bubble, thereby placing the donor stromal surface into contact with the recipient stromal bed for self-adhesion. Staining of the donor disc can help a surgeon properly align the disc in the host bed. A reverse Sinskey hook can be used for final positioning to tuck the donor edges anterior to the recipient bed edges to inhibit later dislodgement. See, Terry et al., Small Incision Deep Lamellar Endothelial Keratoplasty (DLEK) Six Month Results in the First Prospective Clinical Study, Cornea, Volume 24, No. 1, pp. 59-65, January 2005.
Despite the foregoing, there is a need to provide surgical instruments that can facilitate DLEK or stitchless corneal transplantation.